Water well



May 2, 1939. Q EI'RECORDS 2,157,085

WATER WELL Filed June 8, 1938 fig. L

L7755f5'I-EI .77550223 Patented 1939- UNi'rED STATES PATENT OFFICE s 6Claims.

This invention is directed to an improvement in water wells of thepebbled wall-type including the type wherein the pebbled. Wall isartiiiclally provided by introducing pebbles from the upper end of theWell and between the screen and waterbearing sands or wherein thepebbled wall is developed by pumping from the well as initially formedand drawing into contact with the screen the ne sands and pebbles makingup the waterbearing area, the development being continued until thepebbles of the natural deposit forms more or less of a wall surroundingthe screen. The pebbled walll either of the articial or developed type,is utilized as a medium for i'lltering or screening the incoming waterto preclude the passage therethrough of materials, such as fine sand andthe like, so as to prevent such passing through the screen and intothewater vdelivered from the Well by the pump.

In pebbled wells, the pebbles serve to more or less hold back the sandand other water-carried impuritiesvfrom the screen in order to permitthe Water entering the screen to be as clear as possible. Following moreor less continued use of such wells, experience has demonstrated thatfine particles of mud and the like may gradually iind their lway throughthe interstices of the pebbles and accumulate on the exterior of thescreen. This material not only tends to a corrosion of the screen properbut gradually accumulates on the exterior of the screen to eventuallyinterfere seriously with the passage of water through the screenopenings, thereby gradually reducing the capacity of the well.Furthermore, it has been found that the interstices between the pebbles,which for most effective results should remain fully open, graduallyaccumulate a volume of sand and the like which reduces in noinconsiderable degree the volume of water passing through the pebbedlayer in either the artificially developed -pebbled wall or thenaturally developed pebbled Wall.

Of course, these objectionable accumulations on the screen and depositsin the interstices of the pebble layer are dilcult if not impossible toeliminate though attempts have been made by backwashing to clear theseobstructions. 'I'he obstructions, of course, do not noticeably affectsome time vafter donment of the well or the withdrawal of the` screen inparts, the balling out of the pebbles and the rebuilding of the well.

'I'he primary object of the present invention is toprovide a meanswhereby the more or less loose f dition; while at the same time andincident to this movement the pebbles or like particles making up thelayer are moved up relatively to causein such relative movement abreaking down and dislodgment of the sand and other particles which hadpreviously closed or partly closed some of the interstices between thepebbles.

An essential characteristic of the invention is the physical removalfrom the bottom of the well and at or below the lower end of the screenof an appropriate amount of pebbles, as by bailing or the like. Thespace thus provided is more or less immediately lled by the gravitalmovement of the pebble layer which, of course, compels a downwardmovement of this pebble layer throughout its full height or depth.During this gravital movement offthe pebbles, the pebbles next to and incontact with the screen are caused to exert a scouring or rubbingcontact with the outer surface of the screen to thereby remove orsubstantially remove or break the incrustations or accumulations on thescreen and thus substantially clear or more completely free the screenopenings which were previously more 'or less closed by suchaccumulations. Furthermore, 1n the gravital movement of the pebblelayer, there is, of course, more or less relative movement between thepebbles making up that layer with the result of dislodging or breakingaway the particles of sand or the like which have accumulated in many ofthe interstices of the original pebble layer. Thegdislodged sand orother particles will gravitate to the bottom of the well and when thepebbles of the pebble layer reach their iinal and new position, theinterstices are practically clear, with the natural effect of affordingthe passage of a greater amount of water in the same time period.

The invention in its preferred form is illustrated in the accompanyingdrawing, in which:

Figure 1 is an elevation, partly in section, of a water well showing theparts arranged in accord-V ance with the present invention.

In the conventional pebbled well shown in Fig-. ure 1, the outer wellcasing I is tted within the well bore surrounding the inner casing-2 towhich is connected the screen 3 which may be of anyl conventional formor construction. In the particular type of well shown in Figure 1, thepreferable operation is to sink the outer well casing I all the way downto the bottom of the well, positioning the screen and inner well casing2, applying the pebbles from the top of the well to the appropriateheight of the screen between the screen and outer well casing, and thenwithdrawing the outer well screen to a position approximately level withthe top of the screen. The pebbled wall, indicated at 4, is thusinterposed between the screen and the water-bearing sand.

In the artificially developed pebbled wall, the

' pebbles may be delivered from the top of the well through refillingtubes 5 or placed in any appropriate manner. In the developed pebbledwall type, the pumping serves to drawI the natural sand andpebbleatoward the screen with the finer particles of sand passingthrough the screen and the pebbles gradually collecting on the outersurface of the screen to form an appropriate thickness of pebbles toconstitute a pebbled wall.

The essential and characteristic feature of the present invention is ashoe B which, in Figure 1, is shown removably connected at 1 to thebottom of the screen 3. This shoe includes a plate 8 'to rest upon thebottom of the well and spaced' uprights 9 supporting a ring I0 threadedfor connection with the bottom of the screen.

A plug I I is seated in the ring, serving in effect to substantiallyclose the bottom of the screen and yet provide an opening below the plugproper' which is in open communication with the pebbled wall area. Theplug I I is of cementitious material, and is made up of cement andpebbles so that the plug is suiiciently porous to permit the passage ofwater therethrough from below into the screen. The area I2 within theshoe below the plug II is, of course, open to the pebbled area of thewall and during the formation of this wall, either artificially or indevelopment, the pebbles will iind their way down and accumulate in thespace I2 and serve here as a ltering and screening medium aswell as inthe area immediately surrounding the screen 3.

In this particular type of well, the shoe is secured to the screen andthe plug II applied to the shoe before the screen is introduced into thewell. I

As long as the well is delivering its normal quantity of water, theparts described may remain in the positions indicated, but when noticeis given of a failure of water supply, the choking of the openings inthe screen and the closing of some of the interstices of the pebbledwall are indicated as the cause of the failure of the water supply.Under these conditions, a bailer or other appropriate tool is insertedin the inner well casing 2 downwardly in to contact with the plug II andraised and dropped until the plug proper is broken away. A conventionalbailing operation is then proceeded with, removing not only the parts ofthe plug proper but a material part of the pebbled wall, particularlythat part which may be accumulated within the shoe below the plug thepebbled wall will be removed.

As the pebbled wall is made up of relatively loose pebbles, it is atonce apparent that when the pebbles of the lower portion of this wallare physically removed, the pebbles making up the wall'above the removedportion will tend to move downwardly by gravity to ll the space. In thisdownward movement of the pebbles, the layer of pebbles next the screenwill eectively scrape and scour the exterior surface of the screen,breaking up and removing practically all the accumulations andincrustations on the outer surface of the screen. This will, of course,clear to a very considerable ifnot complete extent the openings In thescreen and restore the screen practically to its original capacity forpermitting water flow.

As the pebbles of the pebbled wall are loose, they will, in the downwardmovement referred to, have a relative action, that is, separate, movetoward and from each other, following an irregular path during suchdownward movement. This will tend to a separation of the pebbles makingup the wall and further tend to dislodge any hardened sand or othermaterial previously accumulated in the interstices between the pebbles,l

and this dislodged material will fall downward, at least to a verymaterial extent and be drawn into the bottom of the well, being ofcourse removed by the bailer or pump, when necessary. The pebbles of thewall in their downward movement will rearrange themselves, forming newinterstices and effectively, at least in a general sense, clear andclean their own surfaces and so more or less completely revitalize thepebbled wall into substantially its original condition so far asitsfiltering efciency is concerned. If insufficient pebbles remain in thewall following this operation to complete the necessary height of thewall relative to the screen, additional pebbles may be added through therefilling tubes 5 or directly between the inner and outer casings, oradditional pebbles developed by the method' originally used in theconstruction of the well.

Following the breaking up of the plug II, and the conclusion of thebailing operation and the consequent downward movement `of the pebblesof the wall, an auxiliary plug I3, shown in Figure 2, is inserted in'the well and fitted into the ring I0 to close the lower end of thescreen substantially as did the original plug II.v 'I'he auxiliary plugI3 is made up of the same material and has the same characteristics asthe original plug I I and may be provided with an element I4 ofappropriate form whereby it-may be conveniently handled during itsinsertion. If, after the original cleaning of the screen as describedand the application of the auxiliary plug I3, the screen again becomesclogged for the reasons noted, the auxiliary plug may be broken awayexactly as was the original plug, the pebbled wall again moved to clearaway obstructions, and a second auxiliary plug applied to complete thewell formation.

In some installations or wells of this type, the outer casing I is movedinto the well bore only vto that depth at which it will be finallypositioned. The screen and inner well casing are then placed within theouter well casing and bailed down to a proper depth to position thescreen opposite the water-bearing sand. In this type of wellconstruction', the screen,. indicated in Figure 3 at I5, is, incident tothe bailing operation, moved below the lower end of the outer wellcasing I until the screen is arranged opposite the water-bearing sand.

In providing in this type of well formation for the use of theimprovement, the lower end of the screen is provided with a shoe I6which has an annular. upper end I1 riveted or otherwise securely xed atI8 to the inner surface of thel screen I5, at the lower end of thelatter. Below the screen, the shoe I6 has an outwardly flaring orconical wall I9 connected at the lower end to a ring 2li fully open atthe bottom and having a cutting edge or margin 2l. 'I'he wall I6 abovethe ring is formed with openings 22 in order to permit the flow of waterand pebbles from the pebbled wall into the shoe I6. 'Ihe maximumdiameter of the shoe is that of the well bore, so that as the screen andattached shoe are bailed down below the outer well casing, the ring 20acts to guide and centralize the screen with respect to the outercasing.

The ring 20 rests upon the bottom of the well and is'fully open to theadmission of water from the water-bearing sand, and to the admission ofpebbles to accumulate within the body of the shoe from the pebbled wallwhich, of course, is provided through the outer well casing and betweenit and the inner casing as the screen and shoe travel downward to theirfinal positions. 'I'he conical formation of the shoe will obviouslynecessitate a well baillng movement which will remove material at leastto a diameter equal to that of the ring 2li. 'I'his ring 20 is, atitsmaximum diameter, suiciently greater than the similar diameter of thescreen as to provide'an annular space around the screen when the well iscompleted for the reception of the pebbles.

As in this type of well construction the shoe, screen and inner wellcasing are bailedto their nal position below the outer well casing, itis necessary that the shoe I6 form an open continuation of the screen inorder to permit the passage and operation of the bailing tool.'Iherefore, the more or less permanentplug II in the -type of wellconstruction described in connecshoe is without any plug proper. Afterthe parts are in the final positions, an auxiliary plug similar to theplug I3 of Figure 2, is introduced through the inner well casing andscreen and finally seated firmly on an annular ring-like projection 23secured on the inner surface of the shoe substantially in line with thelower edge of 'the screen. 'I'his plug forms, therefore an effectiveclosure for the bottom ofthe screen, permitting only the passage ofwater under the suction of the pump through the plug after beingscreened or filtered by the pebble accumulation within the shoe belowthe plug.

In this form, the operation, when it is desired to clean the exteriorsurface of the screen and revitalize the pebbled wall, is identicalwith' that previously described. Appropriate ytools are used to break upthe auxiliary plug within the screen I5 and a bailing operation carriedout to clean out the space within the shoe below the auxiliary plug,permitting the gravital movement of the pebbles of the pebbled wall forexactly the same purpose and with the same eiect as that previouslydescribed.

Of course, the shoe I Ii may be of various designs so long as it hassufficient diameter to insure the formation of a pebble-receiving areaas the shoe and screen move downwardly and so long as the wall of theshoe or the annular portion thereof is freely open for the admission ofwater and pebbles of the pebbled wall.

What is claimed to be new is:

1. A method. of cleaning the exterior of a screen of a pebbled waterwell of incrustations and accumulations, consisting in compelling abodily gravital and relative movement of the pebbles! 1ying adjacent tothe exterior surface of the screen over such surface.

2. A method of cleaning the exterior of a screen of a pebbled waterwell, consisting in undermining the pebbles of the wall in contact withthe screen to cause the same to move under the influence of gravityrelative to the exterior surface of the screen, whereby to cause thepebbles to provide a more or less abrading action on the exteriorsurface of the screen.

3. A method of clearing the interstices between the pebbles of a waterwell, consisting in undermining the foundation of the pebbled wall topermit the pebbles to fall by gravity and at the same time moverelatively to dislodge and break up any accumulations in the intersticesof the original pebbles.

4. A method of scouring the exterior surface of the screen of a pebbledwater well and simultaneously breaking up the accumulations in theinterstices of said wam-consisting in undermining the pebbles adjacentto the screen to cause the same to move frictionally over the exteriorsurface of the screen and at the same time move the pebbles making upthe wall relatively for breaking up and dislodging the accumulations inthe interstices of the pebbles.

5. A pebbled water well having afrangible plug underlying the screenand'spaced from the bottom of the well, said plug serving to prevententry of water through the bottom of the screen, and means for breakingthe plug to permit access to the bottom of the well below the screen andthus permit the hailing out of material below the plug to cause thepebbles to move downwardly relative to the screen.

6. A method of cleaning the exterior of the screen of a completedpebbled water well, consisting lin removing material from the bottom ofthe well below the screen to thereby provide an excavation toward whichthe pebbled wall will gravitate and thereby cause the pebbles of suchwall in contact with the screen to exert an abrad- 1118 action on thesurface of the screen for cleaning the same.

CHESTER E. RECORDS.

